From 14e3bea927c33a97ca8aed937b6edd9ce4557d24 Mon Sep 17 00:00:00 2001
From: Thierry Bordaz <tbordaz@redhat.com>
Date: Fri, 3 Apr 2020 15:23:10 +0200
Subject: [PATCH] Ticket 50905 - intermittent SSL hang with rhds

Bug Description:
	On a successfull sasl bind, a new IO layer (sasl_io_enable) is registered on top of
	the connection. Then sasl bind sends the successful result. Registration is
	done while sasl bind thread holds c_mutex but result is sent while the c_mutex
	is released.

	If a new operation comes in just after c_mutex was released it is
	possible that sasl bind sends the result while the new IO layer is pushed.
        IO layers is partially initialized at that time. It can create sigseg or
	deadlock or...

Fix Description:
	The fix is to protect the send result from IO layer push.
	i.e. move send_ldap_result into c_mutex

https://pagure.io/389-ds-base/issue/50905

Reviewed by: Mark Reynolds (Thanks !!)

Platforms tested: F29

Flag Day: no

Doc impact: no
---
 ldap/servers/slapd/saslbind.c | 10 +++++++---
 1 file changed, 7 insertions(+), 3 deletions(-)

diff --git a/ldap/servers/slapd/saslbind.c b/ldap/servers/slapd/saslbind.c
index 0907c623f..ef29acf71 100644
--- a/ldap/servers/slapd/saslbind.c
+++ b/ldap/servers/slapd/saslbind.c
@@ -1118,12 +1118,16 @@ sasl_check_result:
             /* Enable SASL I/O on the connection */
             PR_EnterMonitor(pb_conn->c_mutex);
             connection_set_io_layer_cb(pb_conn, sasl_io_enable, NULL, NULL);
+
+            /* send successful result before sasl_io_enable can be pushed by another incoming op */
+            send_ldap_result(pb, LDAP_SUCCESS, NULL, NULL, 0, NULL);
+
             PR_ExitMonitor(pb_conn->c_mutex);
+        } else {
+            /* send successful result */
+            send_ldap_result(pb, LDAP_SUCCESS, NULL, NULL, 0, NULL);
         }
 
-        /* send successful result */
-        send_ldap_result(pb, LDAP_SUCCESS, NULL, NULL, 0, NULL);
-
         /* remove the sasl data from the pblock */
         slapi_pblock_set(pb, SLAPI_BIND_RET_SASLCREDS, NULL);
 
-- 
2.25.4